BAGHDAD, Iraq -- Iraq said a U.S. airstrike hit its civilian airport in the southern port city of Basra. The announcement did not mention casualties.

A Pentagon official said two strikes early Thursday were in response to Iraq's firing of anti-aircraft artillery and surface-to-air missiles at allied aircraft patrolling zones declared off-limits to Iraqi planes. U.S. officials declined to say whether a civilian airport had been hit.

Iraq quickly condemned Thursday's strike, which came two days after strikes aimed at radar and communications facilities in the southeast.

"This terrorist act is a breach of international civilian aviation regulations," an announcer on Iraq's state-owned satellite channel said.

The announcer said the attack targeted Basra International Airport's radar system and damaged the terminal building. No further details were announced.

It was unclear whether the airport had military facilities.

A Pentagon official said in Washington that aircraft from the U.S.-British coalition launched two strikes just after midnight Iraq time, one near Basra and the other near Al Kufah in southern Iraq.

The strikes came about 90 minutes after Iraq fired at the allied planes, the official said without specifying the location of the Iraqi attacks.

Navy Lt. Cmdr. Nick Balice, a spokesman for the U.S. Central Command in Florida, had no comment on Iraq's accusation that one strike hit a civilian airport.

Coalition aircraft targeted an air defense mobile radar system and an air defense communications facility in the two missions, Balice said. He declined to say where the Iraqis fired from but said the coalition strikes were not necessarily aimed at the Iraqi facility that provoked them.

U.S. Defense Secretary Donald H. Rumsfeld disclosed last week that he ordered pilots to attack such targets as communications sites, command centers and fiber-optic links in Iraq's air defense network rather than the specific guns and radars used against U.S. and British pilots.

The goal of the new approach is to reduce dangers to fliers while increasing the damage to Iraq's increasingly sophisticated air defense system.

The United States and Britain have patrolled zones in northern and southern Iraq since the 1991 Gulf War, declaring the areas off limits to Iraqi aircraft to protect Kurds in the north and Shiites in the south.

Those patrols routinely launch airstrikes, with allies saying they only respond when Iraq's military radar locks onto their fighter planes. On Sept. 6, American and British warplanes attacked and destroyed Iraq's biggest military compound, H-3, in western Iraq near the Jordanian border, the exiled officers said.

These latest incidents come during high tensions between the United States and Iraq. Exiled Iraqi military officers say U.S. and British warplanes recently have intensified strikes in an apparent effort to undermine Iraq's air defenses as a prelude to war.

President Bush, who has accused Iraqi President Saddam Hussein of stockpiling weapons of mass destruction and harboring terrorists, has said he wants a "regime change" in Baghdad. Bush has not said whether he will go to war to achieve his aim, but he is pushing for a U.N. resolution that could authorize such an attack.

On Wednesday, U.S. defense officials announced a double strike at two southeastern installations. Precision-guided weapons were aimed Tuesday at a radar facility near Al Amarah about 165 miles southeast of Baghdad and a defense communications facility at Tallil, about 170 miles southeast of the capital, according to a U.S. Central Command statement.

The statement did not say how effective that strike was, only that the damage assessment was ongoing.